Hi,
if you're interested in playing with a prototype of GNU gdbm or
OpenLDAP on MPE/iX (only slapd server and tools like ldapsearch,
ldapmodify etc. at present), then you can find it at...
http://www.editcorp.com -> Personal Pages -> Lars Appel
I'm not an LDAP expert, so you'd probably share questions with
HP3000-L, but at least it seemed to me that the client and server
parts worked for what I played with them...
Lars.